Does eating more fruit and vegetables really matter to those of us with diabetes?
According to a health initiative called Fruit & Veggies -- More Matters, fewer than one in seven American adults eat the recommended amount of vegetables. The U.S. government’s recommended amount isn’t much: just two and a half cup-equivalents (two and a half cups of raw or cooked vegetables or vegetable juice, five cups of leafy salad greens, one and one-fourth cups of dried vegetables).
Significantly, what the government considers to be vegetables does not include grains. Nor does the vegetable group include nuts, seeds, and soy products, which are considered protein foods.
Regardless, people with diabetes probably need to eat more veggies. But we have to choose them carefully so they won’t raise our blood glucose levels.
Some vegetables do have a high glycemic index. Baked potatoes have so much starch that they will raise your blood glucose level even more than glucose will. Mashed and boiled potatoes, while not as unhealthy as baked potatoes, have a higher glycemic index than anything made from grain. So please, don’t take a recommendation to eat more veggies as carte blanche to eat potatoes or other high glycemic veggies.
Bottom line? "More" does matter when it comes to eating veggies. In addition, eating more fruit may also be problematic for people with diabetes.
Fruit has fructose
Unlike veggies, where the biggest problem is starch, fruits have little or none of this type of carbohydrate. Instead, all fruits have fructose, and some fruits have a lot of it. While fructose will raise our blood glucose level much less than any other sugar will, it is the most dangerous type of sugar for people with diabetes, because eating more than a small amount of it can lead to insulin resistance, weight gain, and high triglyceride levels.
Most experts consider the fructose in fruit to be safe. So it’s not a concern when we eat a small amount of fruit. But in order to gratify our collective sweet tooth, plant breeders have been so successful in developing fruit crops much sweeter than those found in nature that we now have several fruits with a lot of fructose in them.
Dried fruits such as raisins, dates, and figs are some of the fruits highest in fructose (based on a 100 gram serving). Then come some fruits with added sugar, like canned blueberries and applesauce. But the big surprise is that red or green grapes, including Thompson seedless grapes, are the next highest among fruits. This is followed closely by several common fruit juices (grape, apple, and pomegranate) and canned pineapple. Worth mentioning, too, is that pears and apples are both probably too high in fructose for people with diabetes to eat more than once in a great while -- and even then, portions should be small.
Fruit has carbohydrates
Ranking lowest on the fructose fruit list are California avocados. Many people consider avocados to be one of the healthiest fruits. But they bring up another consideration: the amount of carbohydrates some fruits contain. In a 100 gram serving of California avocados (approximately one-half avocado), there are nine grams of carbohydrates; 100 grams of Florida avocados have eight grams of carbohydrates.
Some fruits that are lowest in carbs are lemons and limes. Of the raw fruits, one of my favorites, the American persimmon, is the highest in carbs, so I rarely eat them.
The amount of carbohydrates that we eat certainly does matter, as carbs will raise our blood glucose level more than a small amount. Other high-ranking carb fruits include dried fruit like cranberries, raisins, and dates. Melons that are high in terms of their glycemic index include watermelon and cantaloupe.
However, these considerations of carbohydrates, fructose, and the glycemic index don’t mean that people with diabetes have to avoid all fruit. Wild blueberries, for example, are famous for their high level of nutrients, and I eat a small amount of them regularly even though a standard serving of one cup has 17 grams of carbohydrates.
In fact, there are four fruits that have so few carbohydrates that I have included them on the list of “Free Foods” that I have maintained on my personal website. While dozens of vegetables are free foods, only avocados, chayote, raspberries, and strawberries meet this criterion.
In short, people who have diabetes should avoid eating more than a small amount of dried fruits, fruit juice, or melons. Choose from the many foods that won’t raise your blood glucose level too much. And for people with diabetes, that is what matters.